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tmv.c
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1 /*
2  * 8088flex TMV file demuxer
3  * Copyright (c) 2009 Daniel Verkamp <daniel at drv.nu>
4  *
5  * This file is part of FFmpeg.
6  *
7  * FFmpeg is free software; you can redistribute it and/or
8  * modify it under the terms of the GNU Lesser General Public
9  * License as published by the Free Software Foundation; either
10  * version 2.1 of the License, or (at your option) any later version.
11  *
12  * FFmpeg is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15  * Lesser General Public License for more details.
16  *
17  * You should have received a copy of the GNU Lesser General Public
18  * License along with FFmpeg; if not, write to the Free Software
19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20  */
21 
22 /**
23  * @file
24  * 8088flex TMV file demuxer
25  * @author Daniel Verkamp
26  * @see http://www.oldskool.org/pc/8088_Corruption
27  */
28 
30 #include "libavutil/intreadwrite.h"
31 #include "avformat.h"
32 #include "internal.h"
33 
34 enum {
35  TMV_PADDING = 0x01,
36  TMV_STEREO = 0x02,
37 };
38 
39 #define TMV_TAG MKTAG('T', 'M', 'A', 'V')
40 
41 typedef struct TMVContext {
42  unsigned audio_chunk_size;
43  unsigned video_chunk_size;
44  unsigned padding;
45  unsigned stream_index;
46 } TMVContext;
47 
48 #define TMV_HEADER_SIZE 12
49 
50 #define PROBE_MIN_SAMPLE_RATE 5000
51 #define PROBE_MAX_FPS 120
52 #define PROBE_MIN_AUDIO_SIZE (PROBE_MIN_SAMPLE_RATE / PROBE_MAX_FPS)
53 
54 static int tmv_probe(AVProbeData *p)
55 {
56  if (AV_RL32(p->buf) == TMV_TAG &&
58  AV_RL16(p->buf+6) >= PROBE_MIN_AUDIO_SIZE &&
59  !p->buf[8] && // compression method
60  p->buf[9] && // char cols
61  p->buf[10]) // char rows
62  return AVPROBE_SCORE_MAX /
63  ((p->buf[9] == 40 && p->buf[10] == 25) ? 1 : 4);
64  return 0;
65 }
66 
68 {
69  TMVContext *tmv = s->priv_data;
70  AVIOContext *pb = s->pb;
71  AVStream *vst, *ast;
72  AVRational fps;
73  unsigned comp_method, char_cols, char_rows, features;
74 
75  if (avio_rl32(pb) != TMV_TAG)
76  return -1;
77 
78  if (!(vst = avformat_new_stream(s, NULL)))
79  return AVERROR(ENOMEM);
80 
81  if (!(ast = avformat_new_stream(s, NULL)))
82  return AVERROR(ENOMEM);
83 
84  ast->codecpar->sample_rate = avio_rl16(pb);
85  if (!ast->codecpar->sample_rate) {
86  av_log(s, AV_LOG_ERROR, "invalid sample rate\n");
87  return -1;
88  }
89 
90  tmv->audio_chunk_size = avio_rl16(pb);
91  if (!tmv->audio_chunk_size) {
92  av_log(s, AV_LOG_ERROR, "invalid audio chunk size\n");
93  return -1;
94  }
95 
96  comp_method = avio_r8(pb);
97  if (comp_method) {
98  av_log(s, AV_LOG_ERROR, "unsupported compression method %d\n",
99  comp_method);
100  return -1;
101  }
102 
103  char_cols = avio_r8(pb);
104  char_rows = avio_r8(pb);
105  tmv->video_chunk_size = char_cols * char_rows * 2;
106 
107  features = avio_r8(pb);
108  if (features & ~(TMV_PADDING | TMV_STEREO)) {
109  av_log(s, AV_LOG_ERROR, "unsupported features 0x%02x\n",
110  features & ~(TMV_PADDING | TMV_STEREO));
111  return -1;
112  }
113 
116  if (features & TMV_STEREO) {
117  ast->codecpar->channels = 2;
119  } else {
120  ast->codecpar->channels = 1;
122  }
124  ast->codecpar->bit_rate = ast->codecpar->sample_rate *
126  avpriv_set_pts_info(ast, 32, 1, ast->codecpar->sample_rate);
127 
128  fps.num = ast->codecpar->sample_rate * ast->codecpar->channels;
129  fps.den = tmv->audio_chunk_size;
130  av_reduce(&fps.num, &fps.den, fps.num, fps.den, 0xFFFFFFFFLL);
131 
135  vst->codecpar->width = char_cols * 8;
136  vst->codecpar->height = char_rows * 8;
137  avpriv_set_pts_info(vst, 32, fps.den, fps.num);
138 
139  if (features & TMV_PADDING)
140  tmv->padding =
141  ((tmv->video_chunk_size + tmv->audio_chunk_size + 511) & ~511) -
142  (tmv->video_chunk_size + tmv->audio_chunk_size);
143 
144  vst->codecpar->bit_rate = ((tmv->video_chunk_size + tmv->padding) *
145  fps.num * 8) / fps.den;
146 
147  return 0;
148 }
149 
151 {
152  TMVContext *tmv = s->priv_data;
153  AVIOContext *pb = s->pb;
154  int ret, pkt_size = tmv->stream_index ?
156 
157  if (avio_feof(pb))
158  return AVERROR_EOF;
159 
160  ret = av_get_packet(pb, pkt, pkt_size);
161 
162  if (tmv->stream_index)
163  avio_skip(pb, tmv->padding);
164 
165  pkt->stream_index = tmv->stream_index;
166  tmv->stream_index ^= 1;
167  pkt->flags |= AV_PKT_FLAG_KEY;
168 
169  return ret;
170 }
171 
172 static int tmv_read_seek(AVFormatContext *s, int stream_index,
173  int64_t timestamp, int flags)
174 {
175  TMVContext *tmv = s->priv_data;
176  int64_t pos;
177 
178  if (stream_index)
179  return -1;
180 
181  pos = timestamp *
182  (tmv->audio_chunk_size + tmv->video_chunk_size + tmv->padding);
183 
184  if (avio_seek(s->pb, pos + TMV_HEADER_SIZE, SEEK_SET) < 0)
185  return -1;
186  tmv->stream_index = 0;
187  return 0;
188 }
189 
191  .name = "tmv",
192  .long_name = NULL_IF_CONFIG_SMALL("8088flex TMV"),
193  .priv_data_size = sizeof(TMVContext),
199 };
#define NULL
Definition: coverity.c:32
const char * s
Definition: avisynth_c.h:631
Bytestream IO Context.
Definition: avio.h:147
Definition: tmv.c:41
void avpriv_set_pts_info(AVStream *s, int pts_wrap_bits, unsigned int pts_num, unsigned int pts_den)
Set the time base and wrapping info for a given stream.
Definition: utils.c:4493
static int read_seek(AVFormatContext *ctx, int stream_index, int64_t timestamp, int flags)
Definition: libcdio.c:153
enum AVCodecID codec_id
Specific type of the encoded data (the codec used).
Definition: avcodec.h:3939
int num
numerator
Definition: rational.h:44
int64_t avio_seek(AVIOContext *s, int64_t offset, int whence)
fseek() equivalent for AVIOContext.
Definition: aviobuf.c:230
int64_t avio_skip(AVIOContext *s, int64_t offset)
Skip given number of bytes forward.
Definition: aviobuf.c:304
static int tmv_read_header(AVFormatContext *s)
Definition: tmv.c:67
static AVPacket pkt
#define AV_CH_LAYOUT_STEREO
uint64_t_TMPL AV_WL64 unsigned int_TMPL AV_WL32 unsigned int_TMPL AV_WL24 unsigned int_TMPL AV_RL16
Definition: bytestream.h:87
#define PROBE_MIN_SAMPLE_RATE
Definition: tmv.c:50
Format I/O context.
Definition: avformat.h:1325
AVInputFormat ff_tmv_demuxer
Definition: tmv.c:190
static int tmv_read_packet(AVFormatContext *s, AVPacket *pkt)
Definition: tmv.c:150
int width
Video only.
Definition: avcodec.h:4005
8 bits with AV_PIX_FMT_RGB32 palette
Definition: pixfmt.h:73
AVStream * avformat_new_stream(AVFormatContext *s, const AVCodec *c)
Add a new stream to a media file.
Definition: utils.c:4131
static int tmv_probe(AVProbeData *p)
Definition: tmv.c:54
#define AVERROR_EOF
End of file.
Definition: error.h:55
int av_get_packet(AVIOContext *s, AVPacket *pkt, int size)
Allocate and read the payload of a packet and initialize its fields with default values.
Definition: utils.c:260
uint64_t channel_layout
Audio only.
Definition: avcodec.h:4041
#define av_log(a,...)
int64_t bit_rate
The average bitrate of the encoded data (in bits per second).
Definition: avcodec.h:3968
#define AV_PKT_FLAG_KEY
The packet contains a keyframe.
Definition: avcodec.h:1620
unsigned padding
Definition: tmv.c:44
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:176
unsigned int avio_rl32(AVIOContext *s)
Definition: aviobuf.c:720
#define AVERROR(e)
Definition: error.h:43
static int tmv_read_seek(AVFormatContext *s, int stream_index, int64_t timestamp, int flags)
Definition: tmv.c:172
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification. ...
Definition: internal.h:176
unsigned audio_chunk_size
Definition: tmv.c:42
enum AVMediaType codec_type
General type of the encoded data.
Definition: avcodec.h:3935
#define TMV_TAG
Definition: tmv.c:39
int flags
A combination of AV_PKT_FLAG values.
Definition: avcodec.h:1594
int avio_r8(AVIOContext *s)
Definition: aviobuf.c:589
int av_reduce(int *dst_num, int *dst_den, int64_t num, int64_t den, int64_t max)
Reduce a fraction.
Definition: rational.c:35
unsigned char * buf
Buffer must have AVPROBE_PADDING_SIZE of extra allocated bytes filled with zero.
Definition: avformat.h:461
audio channel layout utility functions
unsigned video_chunk_size
Definition: tmv.c:43
static int read_probe(AVProbeData *pd)
Definition: jvdec.c:55
#define TMV_HEADER_SIZE
Definition: tmv.c:48
static int read_header(FFV1Context *f)
Definition: ffv1dec.c:638
Stream structure.
Definition: avformat.h:876
static int read_packet(void *opaque, uint8_t *buf, int buf_size)
Definition: avio_reading.c:42
#define PROBE_MIN_AUDIO_SIZE
Definition: tmv.c:52
AVIOContext * pb
I/O context.
Definition: avformat.h:1367
#define AVFMT_GENERIC_INDEX
Use generic index building code.
Definition: avformat.h:485
rational number numerator/denominator
Definition: rational.h:43
This structure contains the data a format has to probe a file.
Definition: avformat.h:459
static int flags
Definition: cpu.c:47
int sample_rate
Audio only.
Definition: avcodec.h:4049
#define AVPROBE_SCORE_MAX
maximum score
Definition: avformat.h:471
unsigned int avio_rl16(AVIOContext *s)
Definition: aviobuf.c:704
Main libavformat public API header.
int den
denominator
Definition: rational.h:45
void * priv_data
Format private data.
Definition: avformat.h:1353
int bits_per_coded_sample
The number of bits per sample in the codedwords.
Definition: avcodec.h:3981
int channels
Audio only.
Definition: avcodec.h:4045
Definition: tmv.c:36
const char * name
A comma separated list of short names for the format.
Definition: avformat.h:660
AVCodecParameters * codecpar
Definition: avformat.h:1228
int avio_feof(AVIOContext *s)
feof() equivalent for AVIOContext.
Definition: aviobuf.c:328
int stream_index
Definition: avcodec.h:1590
#define AV_CH_LAYOUT_MONO
uint64_t_TMPL AV_WL64 unsigned int_TMPL AV_RL32
Definition: bytestream.h:87
This structure stores compressed data.
Definition: avcodec.h:1565
unsigned stream_index
Definition: tmv.c:45